On trying to configure the Business Intent in an environment that has 2 clusters of Aria Operations 8.18.x integrated to a single vCenter Server Appliance 8.0.x, it allow to save but after some time it will show a red bullet with the following message:
"The rules of Cluster CLUSTER_NAME, are already managed by another VMware Aria Operations instance ARIA_OPS_NAME"
Aria Operations 8.18.x
vCenter Server Appliance 8.0.x
Configuration not supported, this error will show because the Business Intent configured on the first node will prevent other clusters to have the same level of control on vCenter.
It is not possible to have 2 clusters defining the Workload Placements on a single vCenter.
If the objective is to get a different cluster than the originally integrated to vCenter to handle with the Workload Placement > Business Intent, then the first cluster where it is configured shall have it's configuration cleared before configuring the tags on the other cluster.